Insulation element and method for introducing winding elements into grooves on an armature

ABSTRACT

The present invention relates to an insulator element for lining at least one armature slot of an electrical machine. 
     According to the invention, it is provided that the insulator element ( 10 ) has at least one plastic element ( 11 ), which is intended for lining an armature slot. 
     The present invention also relates to methods for inserting winding elements into the slots of an armature. 
     The present invention further relates to apparatuses for performing the methods of the invention.

BACKGROUND OF THE INVENTION

The present invention relates to an insulator element for lining atleast one armature slot of an electrical machine. The present inventionfurthermore relates to a method for inserting winding elements into theslots of an armature and to an apparatus for performing the method.

PRIOR ART

It is known to line the slots of the armature of an electrical machinewith the thinnest possible strips of paper. Lining the slots in this wayserves to avoid damage to the winding elements, which for instance arein the form of painted copper wires, both in assembly and in offsettingat the sharp stamped edges of the lamination packets. The paperinsulation used also offers a clamping action on the winding elements inthe axial direction, so that the armature can be turned upon assembly.However, a paper insulation in the armature slot of this kind does notoffer a radial hold for the winding elements. The radial change inlocation of the winding elements that is thus possible can adverselyaffect the initial imbalance of the armature. In addition to theintroduction of the paper insulation, still another operation, known as“widening”, is necessary to make it possible to introduce the windingelements, for instance in the form of copper wires, into the slots. As afurther work step, the armature is often also impregnated with epoxyresin by means of immersion rolling. This positionally fixes the windingelements together with the paper in the armature slot. Also by means ofthis work step, a thermal binding to the armature packet can beattained. A disadvantage of this known procedure is that introducing thepaper strips and the subsequent work steps are complicated, which is whyespecially in automated procedures, long cycle times are unavoidable.

SUMMARY OF THE INVENTION

Because the insulator element of the invention has at least one plasticelement that is intended for lining an armature slot, the lining processcan be performed quickly, which makes short cycle times possible in anautomated procedure.

Preferably, each plastic element provided for lining an armature slot istubular. The length of the tubular plastic elements is preferablyadapted to the length of the armature slots. Because of the tubularshape of the plastic elements, it is possible to adapt both to the shapeof the armature slot and to the geometry of the winding elements, whichare in the form of copper conductors, for instance. Thus the windingelements can be disposed in a defined way, which has a favorable effecton the initial imbalance of the armature.

It is also preferably provided that the plastic element has a rib on itsoutside. This rib makes it possible for the further portions of theplastic element to be made with extremely thin walls, since the riblends adequate strength.

The rib can be provided in order to close the armature slot when theplastic element is introduced into the armature slot. This closure ofthe armature slot has a favorable effect on armature noise, forinstance.

The internal cross section of the plastic element can be substantiallyin the form of a figure-8. Preferably, the upper and lower portions ofthe 8 are joined to one another.

Preferably, the plastic element has at least one longitudinal furrow onits inside. By this at least one longitudinal furrow, an axial fixationin the plastic element is made possible, both on the inner side and onthe outer side. Moreover, the at least one longitudinal furrow assuresnot only a compensation for tolerances between the slot and the windingelements but also that the potting composition used in an ensuingimpregnation bathes the conductors on both the inside and outside. As aresult, an optimal connection of the individual components (armaturepacket, insulator element and winding elements) can be assured.

Especially with a view to automated assembly, it can be advantageousthat a plurality of plastic elements are connected to one another by atleast one first connecting element in such a way that their mutuallocation corresponds to the mutual location of a plurality of armatureslots.

To enable problem-free introduction of the winding elements into theplastic elements, the first connecting element can have one or morewinding guide faces.

In an especially preferred embodiment, the first connecting element isannular. On an annular connecting element, a number of plastic elementscorresponding to the number of armature slots can be disposed, so thatin automated assembly, all the armature slots can be simultaneouslylined with plastic elements.

Particularly for this purpose, it is advantageous if the firstconnecting element connects first adjacent end portions of plasticelements that are disposed essentially parallel.

In this connection, it can be provided that the first annular connectingelement connects the end faces of a plurality of plastic elements, andthat the first annular element has openings, which are adaptedessentially to the cross section of the plastic elements. Theaforementioned winding guide faces can in this respect be providedespecially advantageously in the region of the openings. Moreover, anaccumulation of material on one side of the annular connecting elementcan be achieved, which makes it easier to extrude the thin-walledplastic elements.

Moreover, a second connecting element can be provided. By means of thissecond connecting element, the plastic elements can be fixed in theirmutual location over their full length.

The second connecting element is also preferably annular, especially ifthe first connecting element is annular.

This annular second connecting element can then connect the otheradjacent end portions of the plastic elements that are disposedessentially parallel.

To that end, the annular second connecting element surrounds the plasticelements, preferably in such a way that the outside of the plasticelements rests on the inside of the annular second connecting element oris joined to it.

Especially in this case, it is advantageous that the second connectingelement is connected to the plastic elements via rated breaking points.If desired, after the plastic elements have been introduced into thearmature slots, the second connecting element can be sheared offmanually or by an assembly tool. An ensuing metal-cutting operation forremoving the connecting element is also conceivable, such as turning theouter diameter of the armature on a lathe. By the cooperation of thefirst connecting element and the second connecting element with theplastic elements, the insulator elements thus formed are protectedagainst damage, for instance during shipping. Moreover, such insulatorelements can be stored and/or shipped as bulk goods, since theindividual insulator elements can be effectively prevented from catchingon one another. In contrast to the conventional paper inlays, theinsulator elements of the invention can thus be delivered withconventional “pick and place” equipment without major effort.

The second connecting element can also have at least one guide face,which is intended to facilitate the mounting of the insulator element onthe armature. In this connection, it is for instance conceivable for anannular second connecting element that is disposed on the other endportions of the plastic elements to be widened radially toward the endof the insulator element. In that case, the annular second connectingelement upon introduction of the plastic elements into the armatureslots slides over the armature surface that is interrupted by thearmature slots.

Because the method of the invention for inserting winding elements intothe slots of an armature includes the following steps:

a) introducing an insulator element of one of claims 1-17 into at leastone armature slot; and

b) inserting armature winding elements into the at least one plasticelement,

it is possible, for instance in an automated procedure, to shorten thecycle times markedly. This offers a simple way of meeting the demandsmade in terms of the slot insulation, mechanical strength uponoffsetting of the conductors, automated introduction of the windingelements, for instance in the form of copper wires, and the prefixationof the winding elements in the axial and radial directions.

In the method of the invention, the following further step is preferablyprovided:

c) filling interstices between plastic elements and armature slotsand/or plastic elements and winding elements with potting composition.

This potting composition can for instance be formed by a resin, whichassures an optimal joining of the individual components.

The method of the invention furthermore preferably provides that atleast one connecting element is removed after the introduction of theinsulator element into the slots. The connecting element to be removedcan for instance be formed by the annular second connecting element,which is joined to the plastic elements by the rated breaking points. Inthat case, the annular second connecting element can simply be shearedoff. Especially if rated breaking points are absent, however, ametal-cutting method is also conceivable for removing a connectingelement.

Apparatuses that are suitable for performing the method of the inventionare also covered by the patent scope of the associated claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in further detail below in conjunction withthe associated drawing.

Shown is:

FIG. 1, an exemplary embodiment of the insulator element of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1, part of an overall circular-annular insulator element 10 isshown. The insulator element 10 has many plastic elements 11, which areembodied tubularly. The internal cross section 13 of the tubular plasticelements 11 is substantially in the form of a FIG. 8, as can be seenfrom the frontmost plastic element that is shown partly cut away.

All the plastic elements 11 have a rib 12 on their outside. The ribs 12lend adequate strength so that the remaining portions of the plasticelements 11 can be made with extremely thin walls; injection molding inparticular can be considered for the production method.

The many parallel plastic elements 11, all disposed annularly, arejoined together by a first annular connecting element 14. In theembodiment shown, the first annular connecting element 14 connects theend faces on one end of the plastic elements 11. The annular firstconnecting element 14 also has many openings, which are adaptedessentially to the cross section of the plastic elements 11. Althoughthis is not shown in detail in FIG. 1, the annular first connectingelement 14 has many winding guide faces 15, which are intended tofacilitate the introduction of winding elements.

In the region of the other end portion of the plastic elements 11, alikewise annular second connecting element 17 is provided, whichsurrounds the plastic elements 11. The annular second connecting element17 is connected to the plastic elements 11 via rated breaking points 18.This makes it possible for the second connecting element 17, after theplastic elements 11 have been introduced into the armature slots, to beremoved by a simple shearing operation. The annular second connectingelement 17 has an approximately semicircular cross section, andcorresponding partitions 20 are provided to reinforce the annular secondconnecting element 17. Because of the approximately semicircular crosssection of this connecting element 17, a guide face 19 is formed, whichwidens radially in the direction of the end of the insulator element 10.This guide face 19 makes it possible for the annular second connectingelement 17 to be simply slipped over the edge of the end face of anarmature so that it can then slide over the cylindrical outer face ofthe armature when the plastic elements 11 are introduced into the slotsof the armature.

The insulator element 10 shown in FIG. 1 can especially advantageouslybe used with the method of the invention, if this method is done inautomated fashion. To that end, the plastic elements 11 are firstoriented relative to the armature slots, and then the plastic elements11 are introduced into the armature slots, with the second connectingelement 17 sliding as noted over the cylindrical surface, interrupted bythe slots, of the armature. Since once the plastic elements 11 have beenintroduced into the armature slots, which are then closed by the ribs12, the second connecting element protrudes past the surface of thearmature, this connecting element is preferably removed, for instance bymeans of a shearing operation, which can be automated.

By means of the method of the invention, performed as described, all theslots of the armature are simultaneously lined with the plastic elements11, which compared to the conventional lining with paper makes for aconsiderable saving of time.

The above description of the exemplary embodiments of the presentinvention is intended solely for the sake of illustration and is notmeant to limit the invention. Within the scope of the invention, variouschanges and modifications can be made without departing from the scopeof the invention or its equivalents.

What is claimed is:
 1. An insulator element for lining at least onearmature slot of an electrical machine, characterized in that theinsulator element (10) has at least one plastic element (11), which isintended for lining an armature slot, each plastic element (11) intendedto line one armature slot is tubular, the plastic element (11) has a rib(12) on its side which is directed to an outside of the insulatorelement (10), the rib (12) is intended to close the armature slot whenthe plastic element (11) is introduced into the armature slot, and aplurality of plastic elements (11) are connected to one another by atleast one first connecting element (14) in such a way that their mutuallocation corresponds to the mutual location of a plurality of armatureslots.
 2. The insulator element of claim 1, characterized in that theinternal cross section (13) of the plastic element (11) is substantiallyin the form of a figure-8.
 3. The insulator element of claim 1,characterized in that the plastic element (11) has at least onelongitudinal furrow on its inside.
 4. The insulator element of claim 1,characterized in that the first connecting element (14) has one or morewinding guide faces (15), which are intended to facilitate theIntroduction of winding elements.
 5. The insulator element claim 1,characterized in that the first connecting element (14) is annular. 6.The insulator element of claim 5, characterized in that the firstannular connecting element (14) connects the end faces of a plurality ofplastic elements (11), and that the first annular element has openings(16), which are adapted essentially to the cross section of the plasticelements (11).
 7. The insulator element claim 1, characterized in thatthe first connecting element (14) connects first adjacent end portionsof plastic elements (11) that are disposed essentially parallel.
 8. Theinsulator element for lining at least one armature slot of an electricalmachine, characterized in that the insulator element (10) has at leastone plastic element (11), which is intended for lining an armature slot,each plastic element (11), intended to line one armature slot istubular, the plastic element (11) has a rib (12) on its side which isdirected to an outside of the insulator element (10), the rib (12) isintended to close the armature slot when the plastic element (11) isintroduced into the armature slot, and a second connecting element (17)is provided.
 9. An insulator element of claim 8, characterized in thatthe second connecting element (17) is annular.
 10. The insulator elementof claim 9, characterized in that the annular second connecting element(17) connects the other adjacent end portions of the plastic elements(11) that are disposed essentially parallel.
 11. The insulator elementclaim 9, characterized in that the annular second connecting element(17) surrounds the plastic elements (11).
 12. The insulator elementclaim 8, characterized in that the second connecting element (17) isconnected to the plastic elements (11) via rated breaking points (18).13. The insulator element claim 8, characterized In that the secondconnecting element (17) has at least one guide face (19), which isintended to facilitate the mounting of the insulator element (10) on thearmature.
 14. A method for inserting winding elements into the slots ofan armature, having the following steps: a) introducing an insulatorelement (10) of claim 1 into at least one armature slot; b) insertingarmature winding elements into the at least one plastic element (11) c)forming the at least one plastic element (11) tubular; d) providing theat least one plastic element (11) with a rib (12) on its outside, whichrib is directed to an outside of an insulator element (10); e) closingthe armature slot by the rib (12) when the plastic element (11) isintroduced into it, and f) removing at least one connecting element (14,17) after the introduction of the insulator element (10) into the slots.15. The method of claim 14, characterized in that it includes thefollowing further step: c) filling interstices between plastic elements(11) and armature slots and/or plastic elements and winding elementswith potting composition.
 16. An apparatus for performing the method ofclaim 14.